The ongoing standalone Long Term Evolution (LTE) in Unlicensed spectrum forum (MulteFire) and Third Generation Partnership Project (3GPP) Release (Rel) 14 work item on uplink License Assisted Access (LAA) allows LTE User Equipment devices (UEs) to transmit on the uplink in the unlicensed 5 gigahertz (GHz) or license-shared 3.5 GHz radio spectrum. These uplink transmissions generally need to perform Listen-Before-Talk (LBT) prior to accessing the channel.
Today, the unlicensed 5 GHz spectrum is mainly used by equipment implementing the IEEE 802.11 Wireless Local Area Network (WLAN) standard, also known under its marketing brand as “Wi-Fi.”